| 1. |
- Abbas, Muhammad Tahir, et al.
(författare)
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An adaptive approach to vehicle trajectory prediction using multimodel Kalman filter
- 2020
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Ingår i: European transactions on telecommunications. - : Wiley-Blackwell. - 1124-318X .- 2161-3915.
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Tidskriftsartikel (refereegranskat)abstract
- With the aim to improve road safety services in critical situations, vehicle trajectory and future location prediction are important tasks. An infinite set of possible future trajectories can exit depending on the current state of vehicle motion. In this paper, we present a multimodel-based Extended Kalman Filter (EKF), which is able to predict a set of possible scenarios for vehicle future location. Five different EKF models are proposed in which the current state of a vehicle exists, particularly, a vehicle at intersection or on a curve path. EKF with Interacting Multiple Model framework is explored combinedly for mathematical model creation and probability calculation for that model to be selected for prediction. Three different parameters are considered to create a state vector matrix, which includes vehicle position, velocity, and distance of the vehicle from the intersection. Future location of a vehicle is then used by the software-defined networking controller to further enhance the safety and packet delivery services by the process of flow rule installation intelligently to that specific area only. This way of flow rule installation keeps the controller away from irrelevant areas to install rules, hence, reduces the network overhead exponentially. Proposed models are created and tested in MATLAB with real-time global positioning system logs from Jeju, South Korea.
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| 2. |
- Abbas, Muhammad Tahir, et al.
(författare)
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Guidelines for an Energy Efficient Tuning of the NB-IoT Stack
- 2020
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Ingår i: 45th IEEE Conference on Local Computer Networks (LCN). - : IEEE Communications Society. ; , s. 60-69
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Konferensbidrag (refereegranskat)abstract
- In this paper, we study the energy consumptionof Narrowband IoT devices. The paper suggests that key tosaving energy for NB-IoT devices is the usage of full Discontinuous Reception (DRX), including the use of connected-mode DRX (cDRX): In some cases, cDRX reduced the energy consumption over a 10-year period with as much as 50%. However, the paper also suggests that tunable parameters, such as the inactivity timer, do have a significant impact. On the basis of our findings, guidelines are provided on how to tune the NB-IoT device so that it meets the target of the 3GPP, i.e., a 5-Wh battery should last for at least 10 years. It is further evident from our results that the energy consumption is largely dependent on the intensity and burstiness of the traffic, and thus could be significantly reduced if data is sent in bursts with less intensity,irrespective of cDRX support.
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| 3. |
- Abbas, Shahrukh, et al.
(författare)
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Impact Analysis of Large-Scale Wind Farms Integration in Weak Transmission Grid from Technical Perspectives
- 2020
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Ingår i: Energies. - : MDPI. - 1996-1073. ; 13:20
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Tidskriftsartikel (refereegranskat)abstract
- The integration of commercial onshore large-scale wind farms into a national grid comes with several technical issues that predominately ensure power quality in accordance with respective grid codes. The resulting impacts are complemented with the absorption of larger amounts of reactive power by wind generators. In addition, seasonal variations and inter-farm wake effects further deteriorate the overall system performance and restrict the optimal use of available wind resources. This paper presented an assessment framework to address the power quality issues that have arisen after integrating large-scale wind farms into weak transmission grids, especially considering inter-farm wake effect, seasonal variations, reactive power depletion, and compensation with a variety of voltage-ampere reactive (Var) devices. Herein, we also proposed a recovery of significant active power deficits caused by the wake effect via increasing hub height of wind turbines. For large-scale wind energy penetration, a real case study was considered for three wind farms with a cumulative capacity of 154.4 MW integrated at a Nooriabad Grid in Pakistan to analyze their overall impacts. An actual test system was modeled in MATLAB Simulink for a composite analysis. Simulations were performed for various scenarios to consider wind intermittency, seasonal variations across four seasons, and wake effect. The capacitor banks and various flexible alternating current transmission systems (FACTS) devices were employed for a comparative analysis with and without considering the inter-farm wake effect. The power system parameters along with active and reactive power deficits were considered for comprehensive analysis. Unified power flow controller (UPFC) was found to be the best compensation device through comparative analysis, as it maintained voltage at nearly 1.002 pu, suppressed frequency transient in a range of 49.88-50.17 Hz, and avoided any resonance while maintaining power factors in an allowable range. Moreover, it also enhanced the power handling capability of the power system. The 20 m increase in hub height assisted the recovery of the active power deficit to 48%, which thus minimized the influence of the wake effect.
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| 4. |
- Abbott, Jessica K., et al.
(författare)
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The microevolutionary response to male-limited X-chromosome evolution in Drosophila melanogaster reflects macroevolutionary patterns
- 2020
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Ingår i: Journal of Evolutionary Biology. - : Wiley-Blackwell. - 1010-061X .- 1420-9101. ; 33:6, s. 738-750
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Tidskriftsartikel (refereegranskat)abstract
- Due to its hemizygous inheritance and role in sex determination, the X-chromosome is expected to play an important role in the evolution of sexual dimorphism and to be enriched for sexually antagonistic genetic variation. By forcing the X-chromosome to only be expressed in males over >40 generations, we changed the selection pressures on the X to become similar to those experienced by the Y. This releases the X from any constraints arising from selection in females and should lead to specialization for male fitness, which could occur either via direct effects of X-linked loci or trans-regulation of autosomal loci by the X. We found evidence of masculinization via up-regulation of male-benefit sexually antagonistic genes and down-regulation of X-linked female-benefit genes. Potential artefacts of the experimental evolution protocol are discussed and cannot be wholly discounted, leading to several caveats. Interestingly, we could detect evidence of microevolutionary changes consistent with previously documented macroevolutionary patterns, such as changes in expression consistent with previously established patterns of sexual dimorphism, an increase in the expression of metabolic genes related to mito-nuclear conflict and evidence that dosage compensation effects can be rapidly altered. These results confirm the importance of the X in the evolution of sexual dimorphism and as a source for sexually antagonistic genetic variation and demonstrate that experimental evolution can be a fruitful method for testing theories of sex chromosome evolution.
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| 5. |
- Abelsson, Anna, 1971-, et al.
(författare)
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Caring for patients in the end-of-life from the perspective of undergraduate nursing students
- 2020
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Ingår i: Nursing Forum. - : John Wiley & Sons. - 0029-6473 .- 1744-6198. ; 55:3, s. 433-438
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Tidskriftsartikel (refereegranskat)abstract
- Background: Caring for patients in the end-of-life is an emotionally and physically challenging task. Therefore, undergraduate nursing students (UNS) need opportunities to learn to care for the dying patient. This study aimed to describe UNS' experiences of caring for patients at end-of-life. Methods: Interviews with 16 UNS in their last semester of nursing education were conducted. Data were analyzed with a phenomenological approach. Results: The UNS created a professional relationship with the dying patient. It meant that when the patient was unable to speak for themselves, the UNS could still meet his/her wishes and needs. The UNS believed they could take responsibility for the patient who was no longer able to take responsibility for themselves. Meeting with the patient's family could be experienced with anxiousness but was dependent on the personal chemistry between the patient's family and the UNS. Conclusion: The UNS creates a relationship with the patient and their family. To be knowledgeable about the patient's physical and psychosocial needs means that the UNS can support the patient in the end-of-life phase. Being close to the patient and the family results in an intensity of emotions in the care situation. The UNS can receive support from their colleagues during processing their emotions and creating an experience from their encounters with patients in end-of-life care.
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| 6. |
- Abraham, Getahun Yacob, 1958-
(författare)
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A post-colonial perspective on African education systems
- 2020
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Ingår i: African Journal of Education and Practice. - : International Peer Reviewed Journals and Books (IPRJB). - 2519-0296. ; 6:5, s. 40-54
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this article is to discuss about precolonial and colonial education and the development of the education systems in the postcolonial Africa. The paper will deal with the questions whether there were any education systems in precolonial Africa and motives for introducing the colonial education systems. Further the relation of the colonial education systems with the needs of the local society, the postcolonial education systems and their future will be analysed. Methodology: Postcolonial perspective is a theoretical frame for the study. A desk-research was conducted to identify and select the relevant literature. Content analysis was used as a method to understand, analyse and interpret the literature. Findings: The results of the literature review show that there were socialization mechanisms before colonialism in African societies. Education introduced in its modern form by missionaries was supposed to serve mainly religious purposes and to train low level functionaries by colonial states. Instead of focusing on local realities education was used to teach the glories of the colonial countries, spread their language and culture as well as introduce a new way of life by condemning all that was native. After independence the inherited colonial education systems continued isolating the masses who had no access to the colonial languages. Unique contribution to theory, practice and policy: Findings of this study shows some limitations in African education systems. It is necessary that education policy makers and other concerned stakeholders´ to increase the use of local languages to reach the society at large, to focus on contents relevant to their contexts, to provide both theoretical and skill-based education useful for development of society and to aim towards educating productive, conscious, critical and democratic citizens.
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| 7. |
- Abraham, Getahun Yacob, 1958-, et al.
(författare)
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Internationalisation and Interculturality in Preschool Teacher Education: Whose Agenda?
- 2020
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Ingår i: Internasional Utvecksling i Laerutdanning.
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Konferensbidrag (refereegranskat)abstract
- This study explores the question, how do Karlstad University (KAU) preschool teacher education students perceive their course materials in relation to internationalisation and intercultural practice? Questionnaires were administered through the Survey and Report tool to all students in the program. Out of 648 students who received the questionnaire, 94 (14.5%) replied. Cultural-Historical Activity Theory (CHAT) is used as theoretical perspective for the study, with analysis exploring the CHAT elements of: tools; subjects; rules; community; division of labour; objects; and outcomes. Results of the study show that students recognized the availability of internationalization and intercultural perspective in their courses, and particularly valued opportunities to meet and discuss with practicing preschool teachers working in multicultural and multilingual areas. Results also note challenges with creating opportunity for students to meet students from other countries, either in Sweden or online. Some students also indicated they found it difficult to engage with English language texts that used critical theory or which differed from Nordic contexts. Our research suggests that Swedish student teachers value content which prepares them for working in Sweden with culturally diverse students, but place less value on higher education goals of internationalisation when these are not closely connected to practice.
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| 8. |
- Abraham, Getahun Yacob, 1958-
(författare)
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Internationalisation and international practicum for what and on whose terms?
- 2020. - 2
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Ingår i: Global and Intercultural Competence through Practicum in the Global South.. - Köpenhamn : Københavns Professionshøjskole. ; , s. 22-33
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This paper will investigate the aims of internationalisation and international practicum, with the focus on the later. It is important to consider whether both partners in the exchange receive benefits, and if not to reconsider the practicum arrangements to ensure greater equity of benefit. Review of literature in the field and my own experiences as a Swedish university lecturer involved in student teacher practica will be the base for this paper. Some preliminary results of my literature review show that practicum in the South mainly focuses on giving the teacher students from the North the possibility of intercultural understanding with specific goal of dealing with demographic change taking place in the student teacher´s home country. This demographic change has typically resulted in an increased cultural diversity of students in classrooms (Abraham & von Brömssen, 2018; Bosire & Brigham, 2009; Marx & Moss, 2011; Wiken & Klein, 2017). Experiences show that in the movement of students from the North to the South, economically and politically dominant countries are more likely to dictate the terms of relationships (Bosire & Brigham, 2009; Yang, 2002). Viewed from another perspective, countries considered in the center due to their economic and political influence gain more advantages than countries considered in the periphery (Barnet & Reggie, 1995).
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| 9. |
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| 10. |
- Abramovich, Shoshana, et al.
(författare)
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Some new Hermite-Hadamard and Fejer type inequalities without convexity/concavity
- 2020
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Ingår i: Mathematical Inequalities & Applications. - : Element. - 1331-4343 .- 1848-9966. ; 23:2, s. 447-458
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we discuss the Hermite-Hadamard and Fejer inequalities vis-a-vis the convexity concept. In particular, we derive some new theorems and examples where Hermite-Hadamard and Fejer type inequalities are satisfied without the assumptions of convexity or concavity on the actual interval [a,b]
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